Electromagnet.



PATENTED FEB. 13, 1906.

B. H. MILLER.

BLEOTROMAGNET.

APPLICATION FILED APR. 25.1904.

2 SHEETS-SHEET 1.

INVENTOR.

- ErneatjiMtZZer WYTNESSES ATTO \NEY.

No. 812,511. PATENTED FEB.18, 1906.

E. H. MILLER. ELBGTROMAGNET.

APPLICATION FILED APB.25,1904.

2 SHBETSSHEET 2.

W] TNESSES: 1 INVENTOR.

* ErnestMMiZZeR UNITED STATES PATENT OFFICE.

ERNEST H. MILLER, OF LANCASTER, PENNSYLVANIA, ASSIGNOR OF TWO- THIRDS TOJOHN W. HOLMANAND CHARLES V. ROTE, OF LANCASTER,

PENNSYLVANIA.

ELECTROMAGNET- Specification of Letters Patent.

Patented Feb. 13, 1906.

Application filed April 25, 1904. Serial No. 204,692.

To (I/ZZ whom it may concern.-

Be it known that I, ERNEST H. MILLER, a citizen of the United States,residing at Lancaster, in the county of Lancaster and State ofPennsylvania, have invented certain new and useful Improvements inElectromagnets, of which the following is a specification, referencebeing had therein to the accompanying drawings.

This invention relates to electromagnets, and more particularly to animproved solenoid which I have devised especially for op erating thebrakes of street and railway cars, though it is capable of and designedfor general application.

The primary object of the invention is to provide an improvedelectromagnet or solenoid possessing great power, the describedembodiment having two oppositely-movable cores and two or more coils ateach side of its center, whereby the lines of force are concentrated anda powerful magnetic field pro duced, with the center of attraction atthe center of the solenoid, so that when it is energized its cores willbe drawn inward with great force or power for operating the brakemechanism or other appliances in connection with which it is used.

The invention consists, first, in the novel construction of the solenoidand core; second, in the manner of wiring the solenoid, and, lastly, inthe construction. and combination of various details of construction, aswill hereinafter be fully described and then pointed out in the claims.

In the accompanying drawings, which form a part of this specification,Figure 1 is a top plan view of a solenoid and of a lever systemillustrating one application of my invention, and Fig. 2 a sideelevation thereof. Fig. 3 is a plan view of the solenoid, of theconnections with the controller, and of the wiring; and Fig. 4, alongitudinal section of a modified construction of the solenoid, showingthe cores drawn out. Fig. 5 is a side view of the hanger supporting thelink connecting the brake-levers; Fig. 6, a bottom perspective view ofsaid hanger; Fig. 7, an end view thereof, and Fig. 8 a transversesection on broken line A A of Fig. 5. Fig. 9 is a longitudinal sectionof the solenoid illustrated in Fig. 3, the cores being drawn in. I

Similar numerals indicate like parts throughout the several views.

In the drawings, 7 indicates the solenoid, consisting of a cylinder 8,open at both ends and having coils 1, 2, 3, and 4 arranged, as it were,in two series and so as to throw the center of attraction in the centerof the solenoid, as will be more fully described. The core adapted to beoperated in said cylinder 8 when the solenoid is energized by theelectric current is divided into two sections, or rather there are twocores 9 and 10, which engage opposite ends of cylinder 8, and when thesolenoid is energized these cores are drawn toward the center.

11 indicates a brake-lever pivoted to core 9 at 12, and 13 a brake-leverpivoted to core 10 at 14, said brake-levers being supported by stirrups15 and 16. These brake-levers are connected at or near their centers bya pivoted strut 17, supported by a hanger 18. The hanger 18 has on itsunder side a horizontally-disposed jaw 19, and in said jaw and in thebottom of the hanger are slots or elongated openings 20, lying in thesame general direction as the brake-levers. gaged in the groove formedby jaw 19 and the bottom of the hanger, and it has a pin 21 passingthrough it and rigidly secured therein, the ends of which pin engage insaid openings 20, wherein they are adapted to move.

22 indicates the rods connecting the brakebeams (not shown) with theends of the brakelevers opposite the ends pivoted to the cores of thesolenoid.

23 is a floating lever supported by stirrups 16 and 24 and havingpivoted to the ends thereof brake-rods 25, connecting it wlth thebrake-staffs at opposite ends of the car.

Floating lever 23 on opposite sides of its center is attached to rods 22through chains 27 and spur 26 of said rods.

In operation it being desired to apply the brakes the solenoid isenergized, as will be described, when cores 9 and 10 are retracted,throwing outward the ends of the brake-levers pivoted to the rodsconnecting them with the brake-beams. As the fulcrum-pin 21 of strut 17is engaged with and free to move in elongated slots 20, such movementcompensates for any variation in the distance between the pivotalsupports of the equalizinglevers and the ends of the reciprocating coresin different posit ons of the latter.

Referring to Fig. 3, 28 indicates a controller; 29, a rheostat locatedbetween the con- Strut 17 is entroller and the solenoid; 30, theconductors from the controller to the rheostat, and 31 a branchconductor directly from the controller to the conductor 32, connectedwith the start of the coil 1 of solenoid 7, as shown at 33. The coils ofthis solenoid are so wired that the center of attraction is at thecenter. 34 of the solenoid. In this wiring the finish of coil 1 isconnected with the start of coil 2, as shown by conductor 35. The finishof coil 2 is connected with the finish of coil 3 by conductor 36, andthe start of coil 3 is connected with the start of coil 4 by conductor37, while the finish of coil 4 is grounded through conductor 38. Theresult of this mode of wiring the coils of the solenoid is that anymatter subject to magnetic influence when placed at either end ofcylinder 8 will be drawn to its center and there held, or an iron rodwill be drawn in from either end and will be centered at the center ofsaid cylinder. So, also, the cores 9 and 10, occupying the positionsillustrated in Fig. 3, when the solenoid is energized said cores will bedrawn toward the center of said solenoid, as shown in Fig. 9. In themagnet thus constructed the lines of force are concentrated,

and a powerful magnetic field is produced, the power of the magnet beingmuch greater with the two cores than with a single core, as demonstratedby the fact that with but one division-core introduced into the end ofcylinder 8 and the solenoid being sufficiently energized to draw thecore into the cylinder when one man can withdraw said core against theattraction of the solenoid with the same amount of electrical energy,and with both divisions of the core drawn into said cylinder it isimpossible for the strength of two men, one at the outer end of eachdivision of the core, to produce any effect on said divisions as againstthe attraction of the solenoid. This attraction is as fully exerted ifone of the cores is altogether in the tube before the so lenoid isenergized to draw the other core in.

Fig. 4 illustrates the wiring of a core having six coils. The adjacentcenter coils 39 and 40 have their starts connected by a conductor 41.

I do not restrict myself to the manner of wiring the solenoid, or toother details of con struction herein shown and described, as it isobvious that many alterations may be made therein without departing fromthe principle and scope of my invention.

2. A solenoid having two or more coils at each side of its center withsimilar terminals of its center coils electrically connected, theopposite terminal of one of said center coils being electricallyconnected with a dissimilar terminal of an outer coil, and the latterhaving its other terminal connected with the feed-wire the center andouter coil at the op posite side of the magnet also having similarterminals electrically connected.

3. A solenoid comprising a series of coils with electrical connectionsbetween similar terminals of the center coilsand oppositely movablereciprocating cores working in an opening through the centers of thecoils.

4. A solenoid having a series of coils arranged in corresponding groupsat each side of the center of the magnet with similar ter.- minals ofthe center coils electrically CQIl-r nected together, andoppositely-movable reciprocating cores fitted in an opening through thecenters of the coils.

5. A solenoid having a series of coils encircling a central opening, apair of oppositelymovable reciprocating cores fitted in said opening,and electrical connections between similar terminals of successive coilsfor completing a circuit through the several coils.

6. A solenoid comprising a plurality of coils at each side of itscenter, and a core in twoparts adapted to approach each other when thesolenoid is energized, the center coils having similar terminalsconnected and an opposite terminal of one of said center :00

coils connected with a similar terminal of one of the outer coils,dissimilar terminals of the opposite center and outer coils beingconnected, and the opposite terminal of the latter coil being connectedwith the feed-wire, sub- 105 stantially as described,

ERNEST H. MILLER. Witnesses:

C. G. BAssLER, WM. R. GERHART.

